a. Field of Invention
The invention relates generally to stretch wrapping loads, such as stacked boxes and the like. More specifically, it relates to a converter and wrapping system wherein the film is converted from sheet to rope before engaging loads to be wrapped.
b. Description of Related Art
The following patents are representative of wrapping devices and systems:
U.S. Pat. No. 6,874,297 B2 to Solis et al. describes an apparatus and method for wrapping a load under tension with a web of stretch wrap flexible material and then binding the wrapping material to the load by compressing the end of the flexible material into a rope-like configuration. The rope formed is wound around the load at least one turn. A second turn of the rope around the load is then bound to the first rope with a mechanical twisting tie around the two ropes to prevent unwrapping of the load during transit and storage. A hot wire cutting mechanism cuts the rope and the bound two ropes snap back into position against the wrapped load from the force of the stretch wrap tension.
U.S. Pat. No. 6,729,106 B2 to Wiley describes a stretch-wrapping machine which consists of a revolving ring with a packaging material dispenser mounted to it. The ring revolves about a horizontal axis to dispense the stretch wrap material around a load that is supported by a forklift. The revolving ring is mounted on a track that allows the ring to travel back and forth in a direction perpendicular to the ring. This allows the machine to wrap any load that fits within the ring. This allows the machine to wrap any load that fits within the ring. Thus the length and the weight of the load do not limit the wrapping capability of the machine.
U.S. Pat. No. 6,594,970 B1 to Hyne et al. describes a method and apparatus for wrapping a loop of film about a pallet, which supports a layer of products, and a guide, through which said layer passes, to prevent crushing and/or displacement of the product layer. Subsequent product layers are similarly protected by looping film about a previous loop of film and said guide. The guide is designed to facilitate removal of the film looped thereabout as the product layers are lowered.
U.S. Pat. No. 6,550,222 B2 to DeGrasse describes a top platen device used to maintain stability in loads while the load is wrapped for shipping. The top platen device applies a compressive force to the load to stabilize the load while it is being wrapped. The top platen includes a shaft supporting platen pad which is placed on top of the load. The shaft and platen pad are configured to rotate eccentrically with respect to the geometric center of the top platen in order to rotate with the load about the load's center of rotation.
U.S. Pat. No. 6,293,074 to Lancaster, III et al. describes a leading end of packaging material which is attached to a retainer to hold the leading end of the packaging material as the retainer moves toward the load. The retainer is positioned adjacent the load and packaging material is dispensed from a packaging material dispenser, and relative rotation is provided between the dispenser and a load to wrap packaging material around the load. The packaging material is released from the retainer in response to force applied to the retainer to withdraw it from the wrapped load.
U.S. Pat. No. 6,189,291 to Martin et al. describes a leading end of packaging material grasped in a packaging material holder while a load is wrapped. Packaging material is dispensed from a packaging material dispenser, and relative rotation is provided between the dispenser and a load to wrap packaging material around the load. The packaging material holder is positioned on the rotating surface of a turntable but is isolated from any electrical or fluid power source of a rotatable surface of the turntable. During the wrapping cycle, a spring builds and stores energy as the packaging material holder moves downstream along the turntable, automatically releasing the leading end of the packaging material and automatically grasping a trailing end of the packaging material. At least a portion of the packaging material is cut between the packaging material holder and the load, and the spring releases the stored energy to move the packaging material holder upstream toward the dispenser.
U.S. Pat. No. 6,185,914 B1 to Mackie describes a pre-stretch wrapping device consisting of a base, a pre-stretch station, a vertical drive, and a rotatable load causes a pre-stretched web to become wrapped around the load under controlled tension. The pre-stretch station comprises a pair of pre-stretch rollers located on a pivotal frame, a spring which opposes the pivotal movement of the frame relative to the base, a roller motor, and a sensor located between the frame and the base. The sensor monitors relative movement of the frame from the base and a controller in response to signals from the sensor controls the operation of the roller motor.
U.S. Pat. No. 6,185,900 B1 to Martin et al. describes a leading end of packaging material grasped in a packaging material holder while a load is wrapped. Packaging material is dispensed from a packaging material dispenser, and relative rotation is provided between the dispenser and a load to wrap packaging material around the load. The packaging material holder is positioned on the rotating surface of a turntable but is isolated from any electrical or fluid power source of a rotatable surface of the turntable. During the wrapping cycle, a spring builds and stores energy as the packaging material moves downstream along the turntable, automatically releasing the leading end of the packaging material and automatically grasping a trailing end of the packaging material. At least a portion of the packaging material is cut between the packaging material holder and the load, and the spring releases the stored energy to move the packaging material holder upstream toward the dispenser.
U.S. Pat. No. 5,515,973 to Sharp describes a system of wrapping and securing together the components of a bulk package including a bottom tray element and a top cap element with an integral web of plastic material. The plastic material, while in a rope-like configuration, is looped about only a single pair of diagonally opposed corners of each of the top cap element and bottom tray element. The tail or terminal end of the web is secured in place by being positioned between a wrap convolution and the bulk package.
U.S. Pat. No. 5,031,771 to Lancaster describes a wrapping apparatus having a frame, a reciprocally driven carriage moveably mounted on the frame, the carriage being adapted to hold a rotatable roll of stretchable film material and a film width varying mechanism. A driven rotatable turntable adapted to support a load is positioned adjacent to the frame, and the leading edge of the film material is held adjacent to the load. A brake is connected to the film roll to restrict movement of the web of material from the roll and the film width varying mechanism is mounted in the material path so that the film web travels through a pivotable “C” shaped assembly of the film width varying mechanism to collapse the film web width so that the web edges are formed into rope configurations connected by a membrane of film. The carriage is driven along the frame in one direction to provide a wrap, stops when the sensing mechanism on the carriage indicates that a junction between units on the load is present to deposit the stretched collapsed film web so that each roped edge is placed on an adjoining vertically positioned unit with the membrane connecting the two units. The carriage carries the film roll to the next or subsequent junctions where the wrap cycle is repeated until the package wrap is complete, at which time the material web is severed from the material roll dispenser.
U.S. Pat. No. 4,845,920 to Lancaster describes a wrapping apparatus having a frame, a reciprocally driven carriage moveably mounted on the frame, the carriage being adapted to hold a rotatable roll of stretchable film material and a film width varying mechanism. A driven rotatable turntable adapted to support a load is positioned adjacent to the frame, and the leading edge of the film material is held adjacent the load. A brake is connected to the film roll to restrict movement of the web of material from the roll and the film width varying mechanism is mounted in the material path so that the film web travels through a pivotable “C” shaped assembly of the film width varying mechanism to collapse the film web width so that the web edges are formed into rope configurations connected by a membrane of film. The carriage is driven along the frame in one direction to provide a wrap, stops when the sensing mechanism on the carriage indicates that a junction between units on the load is present to deposit the stretched collapsed film web so that each roped edge is placed on an adjoining vertically positioned unit with the membrane connecting the two units. The carriage carries the film roll to the next or subsequent junctions where the wrap cycle is repeated until the package wrap is complete, at which time the material web is severed from the material roll dispenser.
U.S. Pat. No. 4,754,594 to Lancaster describes a wrapping apparatus having a frame, a reciprocally driven carriage moveably mounted on the frame, the carriage being adapted to hold a rotatable roll of stretchable film material and a film width varying mechanism. A driven rotatable turntable adapted to support a load is positioned adjacent to the frame, and the leading edge of the film material is held adjacent the load. A brake is connected to the film roll to restrict movement of the web of material from the roll and the film width varying mechanism is mounted in the material path so that the film web travels though a pivotable “C” shaped assembly of the film width varying mechanism to collapse the film web width so that the web edges are formed into rope configurations connected by a membrane of film. The carriage is driven along the frame in one direction to provide a wrap, stops when the sensing mechanism on the carriage indicates that a junction between units on the load is present to deposit the stretched collapsed film web so that each roped edge is placed on an adjoining vertically positioned unit with the membrane connecting the two units. The carriage carries the film roll to the next or subsequent junctions where the wrap cycle is repeated until the package wrap is complete, at which time the material web is severed from the material roll dispenser.
U.S. Pat. No. 4,255,918 to Lancaster et al. describes a wrapping apparatus having a frame, a reciprocally driven carriage moveably mounted on the frame, the carriage being adapted to hold a rotatable roll of stretchable film material and a film width varying mechanism. A driven rotatable turntable adapted to support a load is positioned adjacent to the frame, and the leading edge of the film material is held adjacent the load. A brake is connected to the film roll to restrict movement of the web of material from the roll and the film width varying mechanism is mounted in the material path so that the film web travels through a pivotable “C” shaped assembly of the film width varying mechanism which when pivoted by spring action reduces the film web width, so that the film material is stretched and reduced in width as it leaves the roll. The carriage is driven along the frame in one direction to provide a wrap for a load and returns in an opposite direction while continuing to wrap the load, at which time the material web is severed from the material roll dispenser.
U.S. Pat. No. 4,235,062 to Lancaster, III et al. describes a process for automatically making a spiral wrapped unitary package with a single web of stretchable material to form a netting overwrap. A series of loads, each containing a plurality of units are fed one at a time onto a turntable adjacent a film dispenser with the leading edge of the film from the film dispenser being collapsed in width and held by a clamp mechanism mounted on the turntable. The collapsed film web is spirally wrapped around the load to one end of the load and spirally wrapped around the load to the other end to complete a first cycle defining an overwrap netting configuration with a plurality of symmetrical angular spaces. The turntable is then rotated at least 90° to offset the collapsed film web and a second cycle is repeated with the film web being spirally wrapped to overlie part of the originally spirally wrapped film web and reduce the angularly shaped spaces formed by the first cycle. On the return of the collapsed film web is tucked under a portion of the collapsed film wrapped around the load.
U.S. Pat. No. 4,204,377 to Lancaster et al. describes an apparatus and process for automatically making spiral wrapped unitary package having a netting overwrap. In the apparatus a series of loads, each containing a plurality of units are fed one at a time onto a turntable adjacent a netting dispenser with the leading edge of the netting from the netting dispenser being held by a clamp mechanism mounted on the turntable. The netting is spirally wrapped around the load and is then formed into a rope-like configuration by a roper mechanism, with the roped netting being wrapped around the turntable clamp mechanism, at which time the roped netting is clamped by a clamping, tucking and cutting mechanism. The clamping, tucking and cutting mechanism tucks the portion of the roped wrap between the load and the roped netting wrapped around the clamp mechanism and severs the roped netting as the turntable clamp mechanism is retracted below the edge of the turntable causing the roped overwrap to attempt to return to its memory position, holding the severed end of the roped netting in a fixed position as the clamping, tucking and cutting mechanism is raised out of the contracting roped wrap. The new leading edge of the netting is held by the clamping, tucking and cutting mechanism which carries the leading edge back towards the turntable clamp mechanism allowing the netting to be clamped by the turntable clamp for the next operation, at which time the clamping, tucking and cutting mechanism releases the new leading edge of the netting and is removed from the netting dispensing path.
Notwithstanding the prior art, the present invention is neither taught nor rendered obvious thereby.